we know imx8mp's NVCC_SD2 of sdhc2 can auto switch voltage 1.8v and 3.3v accroding to Speed Mode(DS/HS or UHS).
1. we notice that VIO_SD pin of W8997 can supply 1.8V or 3.3V, but we don't know how to choose the voltage correctly?
2. Is it necessary to make VIO_SD voltage follow NVCC_SD2 voltage? eg. connect NVCC_SD2 to VIO_SD directly.
3. How about this situation that if our hardwre already fixed 1.8V power supply to VIO_SD? can SDR104 work?
Thank you for your reply, @b45499
1、both work on 1.8V or both work on 3.3V.
->> Can sdio SDR104 work? when both work on 3.3V.
->> Can you parse it?
3、It will be ok, you need to add the "no-1-8-v; "
->> As i know adding "no-1-8-v" to sdhc node in dts then the imx8 sdhc driver will disable all UHS mode include SDR104 . Can you check it for me?